Magento Commerce, 2.2.x
Adding an Attribute to a Product

Although attributes are managed primarily from the Stores menu, you can also add new attributes “on the fly” while working on a product. You can choose from the list of existing attributes, or create a new attributeA characteristic or property of a product; anything that describes a product. Examples of product attributes include color, size, weight, and price.. The new attribute is added to the attribute set upon which the product is based.

Add Attribute